Group homes are one of the most commonly used out-of-home placements for youth with mental health and behavioral problems. Despite widespread use, group homes tend to be viewed negatively because there is very sparse research and concern about potential iatrogenic effects of assembling groups of antisocial youth together. However, there is also consensus that there is no viable alternative at present to serve the number and type of youth currently served by group homes. Hence, it is crucial to rapidly advance the evidence base and address concerns about iatrogenic effects to determine whether, how, and for which youth group homes may be effective. Recent research has identified potential core processes to maximize positive outcomes for youth with disruptive behavior disorders across settings, many of which may operate similarly in group homes as in other therapeutic interventions. In addition, there is an existing model of care for group homes, the Teaching Family Model, that shares a conceptual framework and empirically-derived core processes with this evidence base and has shown promising outcomes. The proposed study is designed to provide focused, applicable, and generalizable data on factors associated with outcomes in group homes. Specific aims will examine: (1) outcomes for youth in group homes;(2) effects of theoretically- and empirically-based organizational factors and core processes on outcomes: (3) rates and predictors of iatrogenic effects;and (4) whether adherence to a promising model of group home treatment (the Teaching Family Model) produces more positive outcomes for youth. The sample includes youth served in Teaching Family group homes as welt as youth in the same geographic areas who are served in non-Teaching Family group homes (n=600 youth). The study builds directly from methodology and findings from our recent and ongoing studies of therapeutic foster care and group homes. Knowledge from the proposed study should substantially advance the evidence base on group homes and provide essential information to improve and rigorously evaluate group home treatment for some of the nation's most difficult-to-treat youth.